Binging, purging and fasting more common in overweight, obese young adults

Young adults who are overweight or obese are twice as likely as their leaner peers to binge and purge, use laxatives or diuretics, or force themselves to vomit as a means of controlling their weight, according to a new study led by UCSF Benioff Children's Hospitals.

These "disordered eating behaviors" put young people at risk for depression, alcohol and tobacco use, poor nutritional intake and significant weight gain over time, the researchers reported in their study, appearing in the Journal of General Internal Medicine on June 12, 2018.

The researchers used data from the National Longitudinal Study of Adolescent to Adult Health that tracked 14,322 nationally representative 18- to 24-year-olds.

They found that among females in the obese and overweight category, 29.3 percent reported that they used unhealthy weight-control techniques, versus 15.8 percent of females who were underweight or normal weight. Among males, the prevalence was 15.4 percent and 7.5 percent, respectively.

Heavier Young Adults May Evade Eating Disorder Diagnosis

Although diagnoses for eating disorders such as anorexia and bulimia were twice as likely to occur in the 18- to 24-year-olds who were of normal weight or underweight, this may reflect under-recognition that these conditions exist in heavier young adults, said first author Jason Nagata, MD, a fellow in the Division of Adolescent and Young Adult Medicine and the Eating Disorders Program at UCSF Benioff Children's Hospitals.

"Clinicians and parents should be aware that eating disorders occur in people who are overweight and obese. They should ask if and how young people are trying to lose weight and discourage unsafe practices, which can lead to severe illness and hospitalization."

Ironically, unhealthy weight-control methods may lead to weight gain. A study on identical twin pairs sharing the same body mass index in which one twin used unhealthy ways to lose weight led to them weighing more than their non-dieting sibling, Nagata noted.

"Unhealthy weight control behaviors may predispose to eating disorders, disinhibition and compensatory eating, particularly of calorically dense foods, which can facilitate greater consumption of these foods," he said.

As expected, disordered eating was found to occur more than twice as frequently in females than in males, but more surprising was its association with race and sexual orientation. The young adults who reported their race as Asian/Pacific Islander had 1.66 times the odds of disordered eating, compared with those who said they were white. Young adults who identified as homosexual, lesbian or bisexual had 1.62 times the odds of disordered eating, compared with those who identified as heterosexual.

"Young adulthood is a critical developmental period that is distinct from adolescence and older adulthood, but unfortunately this period has not received sufficient attention within clinical or research circles," said senior author and general internist Kirsten Bibbins-Domingo, MD, PhD, MAS.

"Although they are usually assumed to be healthy, young adults often have poor patterns of health behaviors and are less likely to be engaged in medical care," added Bibbins-Domingo, who is professor of medicine, holds the Lee Goldman, MD, Endowed Chair in Medicine, and is professor and chair of the Department of Epidemiology and Biostatistics at UCSF.

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The research was supported by funding from the American Academy of Pediatrics, the American Pediatric Society and the Norman Schlossberger Research Fund from UCSF.

Co-authors were Andrea Garber, PhD, of the UCSF Division of Adolescent and Young Adult Medicine, Stuart Murray, PhD, of the UCSF Department of Psychiatry and UCSF Weill Institute for Neurosciences, and Jennifer Tabler, PhD, of the University of Texas Rio Grande Valley.

About UCSF: UC San Francisco (UCSF) is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. It includes top-ranked graduate schools of dentistry, medicine, nursing and pharmacy; a graduate division with nationally renowned programs in basic, biomedical, translational and population sciences; and a preeminent biomedical research enterprise. It also includes UCSF Health, which comprises three top-ranked hospitals – UCSF Medical Center and UCSF Benioff Children's Hospitals in San Francisco and Oakland – as well as Langley Porter Psychiatric Hospital and Clinics, UCSF Benioff Children's Physicians and the UCSF Faculty Practice. UCSF Health has affiliations with hospitals and health organizations throughout the Bay Area. Please visit http://www.ucsf.edu/news.